if my conviction (non-violent) was before 1994 can i legally hunt with a crossbow in the state Colorado.
Even though the Colorado State law was amended in 1994, felony offenders are not "grandfathered in" if the offense occurred prior to 1994. The date of your conviction is not relevant. So if you were convicted of a felony level offense, you can't possess a firearm (under Federal law, which would make the Colorado law moot anyway).
So the only issue is whether a crossbow is a firearm. There has been an opinion issued by the Division of Wildlife and the Attorney General that a bow (cross bow or bow and arrow) is a dangerous weapon and falls under CRS 18-12-108 (the law that makes it a crime to possess a firearm or any other dangerous weapon as a felon).
Now, that is not the law. That is the opinion of the Attorney General, who does not make laws. It may very well be that you could be charged and found not guilty (as I read it personally, I don't think a bow is covered under the law). But there is a great chance that you would be charged with a crime for possessing a cross bow as a felon. The issue has not been litigated to the appellate courts in Colorado, so there is no true answer. As a practical matter, you would be charged with a crime most likely.